Aquarium Story – Fresh Water Red Algae Problems

Red Algae Problems

I have a problem I want to tell you about. During the last year or so, i have had some red Algae problems building up in my tank.

Recently I started to ask the question about what this red algae problem could possibly be.

I decided to start looking into the problem to see if there was a simple solution to fixing this issue.

As it turns out, it’s NOT simple. Even identifying this algae is complicated.

Let me explain:

There are many different types of “RED” Algae in the world.

Some of them are more plant-based, some more algae-based and some are not algae or plant at all and are in fact Bacteria.

So half the battle is identifying this algae  and i am still trying to identify it but i am a lot closer now than before. It has definitely been a challenge so far.

Let’s start at the beginning.

My tank is a Freshwater tank. It’s not suppose to get RED algae or at least this type of red algae…

Tank maintenance is done on time and on schedule, levels are good but perhaps over feeding a little might be the only issue. Tank is an established tank that has been running for years now. Very stable.

Why does algae build up in the first place you ask ?

Usually this occurs due to imbalances in the tank. Excess nutrients, too much light, not enough water flow to those dead zones or contamination in your tank can cause algae to appear. Green algae is normal and every tank has some however Red Algae is different and can occur as a result of certain conditions.

For Coralline Red Algae as example, the right conditions need to be present. Even temperature needs to be correct.

Cyanobacteria (the bad stuff) means that your tank really does have some issues and it can occur when things get too far out of whack.

Contamination can occur from spores being transferred from your local fish store. Spores can come in fish water when you get new fish or on plants.

What types of Red algae are we dealing with here then ?

All of the research I’ve done recently suggests that there can be only 3 main types in Fresh water environments (Salt water have more varieties).

Cyanobacteria (can be blue/green or slightly pink or red)
Not an algae at all but a form of bacteria that can occur in Salt water and freshwater aquariums (more on how to treat this below)

Coralline Algae
A calcium based form of red algae that grows on glass, rocks and generally every surface. There are a lot more types in salt water
There is only 1 type that survives in freshwater (so actually rare) and not much information on it.
Name = Pneophyllum Cetinaensis

Common fresh water variety Red algae
Most common type
Name = Audouinella

Ruling out Cyanobacteria

In my testing i decided to rule out Cyanobacteria as I’ve never seen what it looks like in freshwater. The easiest way to do this was to apply Boyd Enterprises Chemi-clean product. They were kind enough to supply me with a test sample.

Following the instructions, the product did not do anything to my tanks Red algae unfortunately. This is a firm indication to me that it is not Cyanobacteria problem and it in fact a calcium based coralline algae (Pneophyllum cetinaensis?) or possibly another variety like Audouinella.

Cyanobacteria and Chemiclean product

Boyd Enterprises did state that the product works by Oxidizing or using some type of an enzyme that oxidizes the water to work on the bacteria. Cyanobacteria do not like oxygen rich environments.

Although my testing of the product produced not results, i was not targeting the correct variety of algae with the correct product.
I have no doubt the product works as advertised on Cyanobacteria.

** Best of all, the product is fish, nitrifying bacteria and invertebrate friendly! You do have to increase oxygen flow however so add more air pumps or bubblers and powerheads!


For more information go to Boyd enterprises website @ http://boyd–

Purchase from My Amazon Affiliate link below (US and Canada) or purchase from Petco stores off the shelf (at participating Petco stores in the U.S. only).

Possible Solutions

Solutions online suggest that the only way to neutralize Coralline Algae is to rebuild the tank and soak the tanks contents in Vinegar and/or hydrogen peroxide.

This is not ideal but rather easier than manually scraping off the stuff. This solution is great for first time tanks that might be used from other people however it’s not ideal in a situation where you have existing fish. Vinegar and hydrogen peroxide is harmful and can kill your fish or make them very sick.

The first idea is to lower the PH gradually to a more neutral PH. In high Calcium based water areas like I am this is more difficult and expensive to manage. Due to requiring the use of adding acids to the water to reach neutral PH levels, every water change must be adjusted accordingly and testing of your water PH and calcium levels have to be done adding more time and effort to keep.

Next I am looking into Algaecides to see if there are fish friendly versions for freshwater aquariums out there. If you are a product manufacturer that has such a product please get in touch with me as i would like to review more eco-friendly products to help solve this problem that I and my viewers are having.

I would love to hear from the community, Please feel free to leave comments (login is required but account is easy to set up!)

My quest continues!


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